PA crossover question HELP

So i have a behringer super x crossover, and im not new to audio but new to the crossover stuff like this but when i set the crossover point for my Mids does it play everything above the knob or everything below the knob?

My 8" mids play 76-5100hz according to the manufactures website.

I have the crossover set to 3.5k on both channels. But they just don't seem right to me. Like something is weird.

Someone please explain.

My amp is a gemini 4000W and i have both channels set to max and then i control everything with my mixer.

This is where i have the crossover points for the mids, the highs dont matter yet because i dont have my tweeters yet, but that's where im confused. Like since theres no knob for a high, does setting the mid knob mean it plays everything below 3.5k and then everything higher than 3.5k will be sent to the High output?)
https://drive.google.com/file/d/0B8LF2iORlqirOGdFN0psMWNiNHFSaHNKek1WNmV2YlpnbjFR/view

(subwoofer crossover set to 75, now to my knowledge this is a low pass filter so it plays everything below 75)
https://drive.google.com/file/d/0B8LF2iORlqireGNJWW5fNnlNMk5OOEhfbGx0ZHpmcmljVGp3/view

Yes, it does sound like in the current configuration you would be having the mids play 75 Hz - 3.5kHz. Not knowing more about your system, the weird sounding mids could be from the lack of tweeters in your system as well as from bad leveling between the bass and midrange elements, it could be also be that the elements are not wired in correct phase.

The best thing for you to do would be investing in a measurement microphone and software. You can get a reasonable one for 50 bucks or so + you would likely need a mic preamp with phantom power as well.